The natural etching of sub-boundary dislocations on {100} diamond surfaces

Rows of pits running approximately in <100> directions on {100} faces of natural diamonds have been observed optically for the first time. The electron micrographs of single-stage carbon replicas revealed that some of the pits in the row were spiral depressions. It is suggested that these rows of pits are formed by selective dissolution of sub-boundaries having both edge and screw components.